Most video surveillance monitoring systems present video data captured by a surveillance camera on one or more monitors as a live video stream. In a multi-camera system, video streams may be presented in multiple video panels within a single large screen monitor using multiplexing technology. Alternatively or in addition, multiple monitors may be used to present the video streams.
When a large number of cameras are used in a surveillance system, the number of screens and/or the number of video panels displayed in each screen becomes unwieldy. For instance, a 12-camera system may be set up to display output from each camera in a separate designated panel on a large-screen monitor. A user monitoring video surveillance data will have to somehow continuously scan the 12 panels on the screen, each presenting a different video stream, in order to monitor all surveillance data. This constant monitoring of large amounts of continuous data is very difficult for users.
Significantly, newer video surveillance systems may incorporate hundreds, or even thousands, of cameras. It is impossible for a user to monitor all of the video data streams at once.
In addition, more often than not there is no active incident or activity to monitor in typical surveillance systems. For example, a camera positioned to monitor a side exit door may only have activity occurring, e.g., people entering and exiting the door, for about 10% of the day on average. The rest of the time, the video stream from this camera comprises an unchanging image of the door. It is very difficult for a user to effectively monitor a video stream that is static 90% of the time without losing concentration, much less hundreds of such video streams.
It is possible in some systems to review video surveillance data by re-playing the stored video data stream at a high speed, thereby reducing the amount of time spent looking at the video stream. However, even if a stored stream of video data that is 8 hours long is played back at 4× speed, it will still take 2 hours to review. Additionally, such review techniques cannot be performed in real-time. A user is always reviewing video data at a time well after it was captured. In a multi-camera surveillance system, the lag and the amount of time required to review captured video data may make it impossible to review all surveillance data within a time period in which the data is still useful.
A system that allows users to efficiently and effectively monitor multiple video streams in a surveillance system as the data is captured is needed.